“It’s part of me. I can’t wait to get up there flying again in my beloved Spitfire. It’s a beautiful aircraft. It fits you like an overcoat.”

It was 100 years ago on April 1 1918 that the Royal Flying Corps and the Royal Naval Air Service merged to create the RAF – the world’s first independent air service.

The Queen has hailed the RAF for “defending our freedom gallantly” as she sent her “heartfelt congratulations” to the service.

A series of events were being held to mark the milestone, including a baton relay.

PA Wire/PA ImagesFormer Spitfire pilot Squadron Leader Allan Scott, 96, prepares to fly as a passenger in a Spitfire as part of the RAF100 commemorations at Biggin Hill Airport in Kent.

PA Wire/PA Images

Stefan Rousseau - PA Images via Getty Images

During a breakfast reception at a building on the Strand, London – formerly Hotel Cecil which was the first headquarters of the RAF – a printed message from the Queen was read out by Aircraftsman Adam Wood.

The 16-year-old from Aylesbury, who is one of the youngest members of the RAF, told the room packed full of dignitaries including the Chief of the Air Staff Air Chief Marshal Sir Stephen Hillier and Chief of the Defence Staff Air Chief Marshal Sir Stuart Peach, that the Queen sent her “heartfelt congratulations” as he read her message.

The Queen has today sent a message to the @RoyalAirForce to mark its 100th birthday.

“The anniversary of the world’s first independent Air Force is of great significance, and it is fitting to pay tribute to the tenacity, skill and sacrifice of the men and women who have served within its ranks over the last century, and who have defended our freedom gallantly,” the Queen said.

“Through its enduring focus on professionalism, excellence and innovation, the Royal Air Force stands as a shining example of inspiration around the world today and for the next generation.

“May the glory and honour that all ranks have bestowed on the Royal Air Force light its pathway to the future guarding our skies and reaching for the stars.”

In our 100th year, we will commemorate those who have gone before, thank our service men and women and inspire the next generation so that together, we can continue to help shape our world for the next 100 years and beyond #RAF100pic.twitter.com/sQ8puifGye

The Queen finished the message with the Latin motto of the RAF, Per Ardua ad Astra, which translates to English as “through adversity to the stars”.

ACM Hillier told the Press Association that as the RAF enters its second century, the anniversary is a “chance to reflect back on a first century of achievement, success, courage and sacrifice”.

Pressed on what the message from the Queen means to the RAF, he said it is “tremendously important”, highlighting how King George V also sent them a message when the service was first formed.

“And now to have Her Majesty the Queen sending a message to her Royal Air Force and recognising what we have achieved in the past and also looking forward to the future, it is a tremendously significant moment for us,” he said.

When asked whether when he first joined the RAF he ever imagined he would have been Chief of the Air Staff during the centenary of the service, ACM Hillier said “No”.

“I joined the Royal Air Force quite a few years ago now, but I joined the Royal Air Force because I had a love of flying, I wanted to be a pilot… but also because I wanted to give myself as many opportunities as possible, to challenge myself and get greater responsibility,” he added.

“I guess that has happened as each year has gone past, and one day I found myself in command of the Royal Air Force – it is just a huge privilege, I am tremendously proud to be in command of the Royal Air Force.

“And on our 100th birthday as well – (it) just makes it even more special. But I do that on behalf of everybody in the Royal Air Force and the Royal Air Force family.”

Steven Paston - PA Images via Getty ImagesThe Founders' Day Service, to commemorate the centenary of the formation of the Royal Air Force at St Clement Danes Church, in London.

Celebrations on Sunday also include a service at St Clement Danes Church, in London, the RAF’s Church, attended by veterans, serving RAF personnel. and former Countdown presenter and honorary Group Captain, Carol Vorderman.

Vorderman, who co-hosted a gala at the Royal Albert Hall on Saturday marking the start of the centenary celebrations, said it was a shame the event was not televised.

“It was really emotional and should have been shown, the various stories that so many members of the public won’t know about,” she added.

Spotted doing a selfie with a number of RAF air cadets on the steps of the Royal Courts of Justice following the start of the baton relay, Vorderman described the service as a “family”.

“Even if you’re not serving personnel it has a wider family, and that is not a cliche, it is the truth,” she said.

“It is very welcoming and it has touched so many millions of lives in different families over the years, and it is wonderful.”